Examination of the
Main Street/Linden Street Intersection,
Waltham, Massachusetts

John S. Allen, May 20-22, 2004

As of May 2004, the Main street/Linden Street/Ellison Park
intersection in Waltham, Massachusetts is under reconstruction. Elements of the
reconstruction include pedestrian crosswalks, new traffic signals, and a new traffic
island. The changes to the intersection appear primarily to be intended to improve
conditions for pedestrians. The photos below were taken on May 18 and 22, 2004, when
construction of traffic islands and wheelchair ramps was nearly complete, but the new
traffic signals had not yet been installed.

This is a five-way intersection, as shown in the map and aerial photo
below. All of the streets are two-way except Ellison Park, which is one-way toward the
intersection, as indicated by the arrow. Traffic is heavy on Linden Street and Main
Street, moderate on Ellison Park, and very light on the stub of a street just south of
Main street which ends at the railroad tracks.

The photo below looks eastward across Linden Street and along the north side of Main
Street.

New wheelchair ramps are visible, along with the old crosswalk across Linden Street
and the absence of crosswalk markings where the pedestrian is crossing Main Street. Now,
let's look at traffic flow in the intersection. Traffic signals currently have three
phases for vehicles entering from different directions:

Right turn from Linden Street onto Main Street, and left turn from Main
Street onto Linden Street. This is shown in the photo above.

Left turn from Ellison Park and Linden Street onto Main street. This
phase is shown in the two photos below, with vehicles coming out of Linden Street and
Ellison Park. As shown in the lower one of these photos, a driver occasionally turns from
Ellison Park all the way to Linden Street, crossing the path of drivers proceeding from
Linden Street, an unusual and likely hazardous maneuver.

Main Street both ways, also allowing right turns on red from Main to
Linden and left from Main onto the stub street. This is shown in the photo below, looking
east across the railroad bridge on Main Street. The photo also shows a new traffic island
in the right foreground.

In addition, there is presently an additional pushbutton-actuated
pedestrian signal phase. I do not know what the signal phasing will be with the new
signals; it might be better than the present phasing. However, the alignment of the new
island is my major concern with the intersection design.

As the photo shows, it seriously narrows the right-hand travel
lane. This narrowing could potentially result in motorists' colliding with the curb or
with each other, and also poses a problem for bicyclists. The bicyclist in the photo below
has chosen to go around the right side of the island in order to avoid the narrowing
channel to its left. It is hard to believe that this installation complies with the
Massachusetts Highway Department's bicycle accommodation guidelines.

Next, we look toward the island from the railroad bridge. The red
arrows in the photo below show the locations of wheelchair ramps.

The ramp on the Main Street side is halfway back along the island, and the continuing
intrusion of the island toward the foreground in the photo does nothing to decrease
pedestrian crossing distance.

The same ramp is indicated by the red arrow in the photo
below, the viewpoint of which is from the north side of the intersection between Ellison
Park (to the right) and Linden Street (to the left). A new pedestrian crossing of Main
Street makes no use of the median island in Main Street (blue arrow) as a pedestrian
refuge.

There is also no convenient ramp to the island for pedestrians headed east on Main
Street, as shown in the photo below.

Large trucks serve a business on the dead-end street south of the railroad bridge.
With the new island, they can not negotiate the left turn from Main Street, as shown in
the photos below. The channel at the end of the island is too narrow to allow them to
avoid a utility pole.

Note also that there is no sidewalk here, although there is a pedestrian pushbutton on
the (old) signal pole in the foreground. Pedestrians must cross the a parking area in the
lower right of the photos and then walk in an awkward location in the street to get the
the pedestrian ramp at the far end of the island which is visible in the photos.

What
might have improved this intersection, and might still be done? First, the easy
possibilities:

Ellison Park is only a local street; residents could exit the
neighborhood at a number of other locations. Ellison Park could be closed off to all but
pedestrian and bicycle traffic without any substantial inconvenience to anyone, and to the
advantage of residents who would then not have to contend with through traffic. Or
possibly, reverse the flow on Ellison Park, to eliminate the crossover left-turns onto
Linden Street and the number of signal phases. (This may actually be in the works with the
new signals, I don't know).

Install a wheelchair ramp near the southwest corner of the new island.

Apply the lessons from this intersection to the design of others in the
future.

And now the more difficult possibilities, given that construction is nearly complete:

Cut back the the island so it does not reduce lane width on Main Street,
or at the very least, cut it back where its reduced size would not increase pedestrian
crossing distance. Also cut it back where it interferes with truck turns from Main Street,
and/or move the utility pole.

Consider moving the new crosswalk to where it can take advantage of the
median as a refuge, and also to the west of Ellison Park (if it still serves one-way
traffic southbound) so pedestrians need not cross as many streams of traffic.